<template>
	<div>
		<router-link tag="div" to="/" class="header-abs" v-show="showAbs">
			<div class="iconfont back-icon">&#xe624;</div>
		</router-link>
		<div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
			<router-link to='/'>
				<div class="iconfont  header-fixed-back">&#xe624;</div>
			</router-link>
			景点详情
		</div>
	</div>
</template>
<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = { opacity }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>
<style lang="stylus" scoped>
@import '~styles/varibles.styl'
.header-abs
	position absolute
	left 0.2rem
	top 0.2rem
	width 0.8rem
	height 0.8rem
	line-height 0.8rem
	text-align center
	border-radius 0.4rem
	background rgba(0, 0, 0, 0.4)
	.back-icon
		color #fff
		font-size 0.4rem
.header-fixed
	position fixed
	z-index 2
	left 0
	top 0
	right 0
	height $headerHeight
	line-height $headerHeight
	overflow hidden
	text-align center
	color #fff
	background $bgColor
	.header-fixed-back
		width 0.64rem
		text-align center
		font-size 0.4rem
		position absolute
		left 0
		top 0
		color #fff
</style>
